Wireless, radio frequency communication systems enable people to communicate with one another over long distances without having to access landline-connected devices such as conventional telephones. While early systems were primarily configured for voice communications, technological improvements have enabled the development of “3-G” (third generation) and similar wireless networks for both voice and high-speed packet data transfer. For example, CDMA-based, “1x-EVDO” (Evolution Data Optimized) wireless communication networks, now implemented in many parts of the U.S. and elsewhere, use the CDMA2000® 3-G mobile telecommunications protocol/specification for the high-speed wireless transmission of both voice and non-voice data. A typical 1x-EVDO wireless network 10 is shown in simplified form in FIG. 1. The network 10 includes one or more fixed base stations 12 having various transceivers and antennae for wireless communications with a number of distributed wireless units such as mobile phones 14a and wireless-equipped portable computer terminals 14b, e.g., laptop computers. For conducting wireless communications between the base stations 12 and the wireless units 14a, 14b, the network 10 utilizes a CDMA (code division multiple access) spread-spectrum multiplexing scheme. In CDMA-based networks, transmissions from wireless units to base stations are across a single frequency bandwidth known as the reverse link 16, e.g., a 1.25 MHz or greater bandwidth centered at a first designated frequency. Generally, each wireless unit 14a, 14b is allocated the entire bandwidth all the time, with the signals from individual wireless units being differentiated from one another using an encoding scheme. Transmissions from base stations to wireless units are across a similar frequency bandwidth (e.g., a 1.25 MHz or greater bandwidth centered at a second designated frequency) known as the forward link 18. The forward and reverse links may each comprise a number of traffic channels and signaling or control channels, the former primarily for carrying voice data, and the latter primarily for carrying the control, synchronization, and other signals required for implementing CDMA communications. Under 1x-EVDO, the network 10 also utilizes another radio channel 20 (e.g., a third 1.25 MHz or greater frequency bandwidth) dedicated to carrying high-speed packet data, with forward data rates up to 3.1 Mbit/s and reverse rates up to 1.8 Mbit/s. The network 10 may be geographically divided into contiguous cells, each serviced by a base station, and/or into sectors, which are portions of a cell typically serviced by different antennae/receivers supported on a single base station.
For high-speed packet data communications over the 1x-EVDO data channel 20, a laptop terminal 14b, for example, will typically be provided with a 1x-EVDO wireless interface card 22, e.g., a miniaturized 1x-EVDO transceiver/chipset, antenna, and computer interface. For example, the wireless interface card 22 may be configured as a PCMCIA card for insertion into a PCMCIA card expansion slot 24 of the laptop. One example of this type of 1x-EVDO wireless interface card is the AirCard® brand from Sierra Wireless. A driver program 26 is provided along with the wireless interface card 22 for controlling the interface card 22 for data transfer over the 1x-EVDO airlink 20. Typical driver programs 26 are compatible with the Microsoft Windows® operating system 28, and support a single laptop computer 14b. For wirelessly transferring data in ongoing operations, e.g., downloading a large file from the Internet 30 to the laptop 14b, the driver 26 controls the interface card 22 in a standard manner to open a communication link between the laptop 14b and the wireless network 10. Depending on the particular characteristics of the wireless network 10 and interface card 22, the link may be “always on.” Data addressed to the interface card 22/laptop 14b is sent in packet form from the Internet 30, possibly through a security firewall 32 of the network 10, through a core IP or other packet data network 34 portion of the network 10, and to a packet data serving node (“PDSN”) 36. From the PDSN 36, the packet data is routed to a packet control function (“PCF”) 38 in place on a radio network controller (“RNC”) 40, which manages the relay of data packets between the PDSN 36 and base stations 12. (As should be appreciated, if the network 10 has more than one RNC, the data addressed to the laptop terminal 14b is sent to the RNC 40 that is linked to the base station 12 in communication with the laptop 14b.) The packet data is sent from the PCF 38 to the base station 12 for transmission to the laptop 14b. The network side may include packet data load generator (“PDLG”) server software 42 for generating data packets for transmission over the air interface 16, 18, 20. Correspondingly, the terminals 14a, 14b will include PDLG client software 43 for receiving 1x-EVDO data packets, which may be part of the driver program 26.
The PDLG server software 42 is used to generate packet data transmissions. Originally, PDLG software was designed to support CDMA “3G-1x” mobile phones. (3G-1x was an early third-generation technology featuring data transmissions of up to 153 kbps on both the forward and reverse links.) In 2001, when 1x-EVDO was introduced (1x-EVDO was originally called “HDR,” which stood for high data rate), the PDLG software was modified to support 1x-EVDO access terminals for generating data call load on 1x-EVDO base stations. By the beginning of 2002, the PDLG software was able to support “Hornet” and “Chester” access terminals, both of which were early 3-G 1x-EVDO access terminal prototypes. In the same year Sierra Wireless introduced the first commercial access terminal, called the AirCard® 575, to support high-speed data calls over the 1x EV-DO network. The PDLG software was revised to support the AirCard® 575.
To test PDLG software 42, it is typically the case that the software is set up and executed in a test environment (e.g., a testing lab) that mimics the actual wireless operating environment, including carrying out multiple calls/transmissions at one time. Thus, the PDLG software 42 is tested in use with a plurality of actual AirCards®, each of which requires a separate laptop terminal 14b to support a single call. Also, the AirCard® driver program 26 only works with the Microsoft Windows® operating system 28, and supports only one AirCard® per laptop. Because of these factors, 1x-EVDO testing facilities are unreliable and expensive to build.
In particular, FIG. 2 shows an existing test facility 44. The facility 44 includes a PDLG client terminal 46 (running Linux), which has multiple network interfaces 48a-48c. One interface 48a is connected to the wireless network 50 (or possibly to an internal network), while the other interfaces 48b, 48c are connected to network interconnection hubs 52a, 52b. For example, each hub 52a, 52b may be a 24-port hub, with one of the ports being connected to the PDLG client terminal and the other 23 ports being respectively connected to a plurality of laptops 54a-54g, each of which is used for supporting a single call/communication. Thus, by using two 24-port hubs and one 4-port hub, it is possible to connect 48 laptops 54a-54g to the PDLG client terminal 46 for testing operation of the PDLG software in the context of 48 simultaneous 1x-EVDO calls. Each laptop 54a-54g includes a network interface 56 or the like, an expansion slot 58 for receiving a PCMCIA card, and an AirCard® 60 (with a PCMCIA connector) connected to the laptop via the expansion slot 58. Similar to as shown in FIG. 1, each laptop 54a-54g runs the Windows® operating system 28 and includes a Windows®-based AirCard® driver program 26. Each AirCard® 60 is connected to the RF interface 62 of the network 50, either wirelessly using the AirCard®'s built-in antenna or via an RF feed cable attached to the AirCard®'s antenna input. The RF interface 62 may be an actual base station, or it may be a transceiver system for simulating the operation of a base station. The laptops 54a-54g, hubs 52a, 52b, and one or more electric fan units 64 are housed in a storage cabinet 66. In operation, a PDLG script 68 is run on the PDLG client terminal 46 to generate the call load on one or more of the laptops 54a-54g. Once the calls are established on the laptops 54a-54g, data is moved between the laptops 54a-54g and a PDLG server terminal 70 located on the PDSN side of the network 50.
Considering the large number of laptop terminals 54a-54g, AirCards® 60, and support components (e.g., fan units 64 and hubs 52a, 52b), as well as the cabinet 66, test facilities 44 are very expensive and time consuming to set up and operate. For example, to build one fully loaded cabinet 66 with forty-eight laptops may cost as much as $70,000. Also, it may involve two to three persons working for up to two weeks to build the physical cabinet and two persons working for two to three weeks to install and configure the laptop terminals 54a-54g and the PDLG client terminal 46. System reliability issues are also a problem, including laptop terminal lock-up due to over heating, computer virus infection exacerbated through the use of the Windows® operating system 28, incompatibility problems between the AirCard® drivers 26 and Windows® 28, and that maintaining hundreds of laptop terminals is very time consuming and prone to error.